Closure cap and method of making same



Nov. 6, 1962 G. J. FOSS ETAL CLOSURE CAP AND METHOD OF MAKING SAME Filed July 7, 1960 INVENTORS G50 J Foss y DAN/EL O. flCrc/Y 3,032,396 Patented Nov. 6, 1962 3,962,396 CLOSURE CAP AND METHOD OF MAKING SAME George J. Foss and Daniel D. Acton, Lancaster, Ohio, assig'uors to Anchor Hocking Glass Corporation, Laucaster, Ohio, a corporation of Delaware Filed July 7, 1968), Ser. No. 41,373 6 Claims. (Cl. 21540) The present invention relates to the sealing art and more particularly to an improved closure cap adapted to be applied to a container to form a sealed package.

Closure caps are widely used to hermetically seal containers. Such closure caps utilize a sealing gasket which cooperates wtih the rim of a container to form a hermetically sealed package. One such sealing gasket which is in use today is a so-called cut-ring type gasket which is cut from a tube of vulcanized rubber or other suitable material and adhered to a gasket-receiving channel formed in the cover of the closure cap by a suitable adhesive.

Another type of gasket also in use today is the socalled flowed-in type gasket which is formed by flowing a gasket material into the gasket-receiving channel of the closure and thereafter heating the closure to cure the gasket material.

Recently, it has become desirable to utilize a closure cap which has a plurality of locking lugs thereon which are adapted to cooperate with the suitable threads on the container to hold the cap in place. With this type of closure it is merely necessary to twist the closure in one direction to remove the cap and to twist it in the opposite direction to re-apply the cap.

However, it has been found that since such twist closures are easily removable, it is possible for someone to tamper with the sealed package on the shelf by unscrewing the cap and removing a part of the contents. This is especially undesirable when such closure caps are used to seal baby-food jars. It has therefore become necessary to provide a suitable tamper-proof feature for the closure cap.

It is also important for the consumer to be able to determine whether a sealed package has lost its vacuum seal regardless of whether the sealed package has been tampered with or not.

Heretofore, the tamper-proof and vacuum indicating features have been extensively used. One such tamperproof feature is to utilize the cover of the closure cap to indicate whether the closure has been tampered with. If there is a vacuum within the container, the cover portion of the closure will be flexed downwardly; however, if there is no vacuum in the container, which indicates that the container has been tampered with or has otherwise lost its vacuum seal, the cover portion will be raised upwardly. The housewife may thus determine the presence or absence of the vacuum either by a visual inspection or by applying pressure to the cover portion and if the cover portion flexes down and the cover snaps back with an audible click, the housewife knows that there is no vacuum in the container.

Heretofore, the cover portions of such closure caps in flexing up and down have utilized the junction between the cover portion and the gasket-receiving channel as a fulcrum. However, it has been found that there is a tendency for deformation or breakdown in the gasketreceiving channel which causes the contour of the cover portion to change, thus interfering with flexing action.

It has also been found that such prior caps did not have the necessary relationship between the height and diameter of the flexible cover or flip panel and the overall height and diameter of the cap and were not of the proper hardness to permit the metal to be released of the stress and strains necessary for the flip panel to flex properly and to return with an audible click.

The present invention overcomes these disadvantages and has for one of its objects an improved closure cap which has an. improved tamper-proof feature thereon.

Another object of the present invention is the provision of an improved closure cap in which the position of the flip panel will indicate the presence or absence of a vacuum within the container.

Another object of the present invention is the provision of an improved closure cap in which there is a proper relationship between the diameter of the cap and the height and diameter of the flip panel to permit flexing of the flip-panel.

Another object of the present invention is the provision of an improved closure cap in which the hardness is such as to permit flexing with an audible click.

Another object of the present invention is to provide an improved method of forming the closure cap having an improved tamper-proof feature.

Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described, or will be indicated in the appended claims, and various advantages not referred to herein will occur to one Skilled in the art upon employment of the invention in practice.

A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings, forming a part of the specification, wherein:

FIG. 1 is a sectional view showing the closure cap of the present invention with its fiip panel in its upward position indicating the absence of a vacuum in the container;

FIG. 2 is a sectional view showing the flip panel in its lowered position indicating the presence of a vacuum in the container;

FIG. 3 is an enlarged exaggerated detail of the flexing bead of the present invention;

FIG. 4 is a sectional view showing the use of the present invention on a different type of closure cap;

FIG. 5 is a sectional view showing one step in the method of making the closure;

FIG. 6 is a sectional view thereof showing the precurling step in the method of making the closure;

FIG. 7 is a sectional view thereof showing the lugforming step in the method of making the closure;

FIG. 8 is a sectional view thereof showing another step in the method of mak ng the closure; and

FIG. 9 is a sectional view thereof showing the final step in the method of making the closure.

Referring more particularly to FIGS. 1 and 2, the closure cap 1 comprises a cover portion 2 and a skirt portion 3. The edge of the skirt portion 3 is curled into a bead 4 and is provided with a plural'ty of locking lugs 5 adapted to cooperate with threads 6 on a container finish 7 to form a sealed package. The cover portion 2 is provided with a gasket-receiving channel 8 formed by a shoulder 9 and has a peripherally upwardly extending bead 10 at the juncture between the skirt portion 3 and the gasket-receiving channel 8 to act as an escapement for any metal of the skirt deflected nwardly as a result of a blow. It will be understood, of cour=e. that, while, for convenience, the present invention will be described in connection with a closure cap having locking lugs 5 and escapement bead 10, it is within the scope of the present invention to use closure caps wh'ch do not have locking lugs 5 and which do not have the escapement bead 10.

A sealing gasket 11 is mounted in the gasket-receiving channel 8. The sealing gasket 11 shown in the drawings is the so-called cut gasket type which is cut from a tube of vulcanized rubber or other suitable material and which is adhered to the gasket-receiving channel 8 by a suitable adhesive. It will be understood, cf course, that the present invention is equally applicable to closure caps which utilized so-called flowed-in type gaskets in which a suitable gasket material, such as plastisol or the like, is flowed into the gasket-receiving channel 8 and heat is applied to cure the gasket.

A peripheral flexing bead 15 is formed in the cover portion 2 and a dome-shaped button or flip panel 16 is formed which is adapted to flex upwardly (FIG. 1) or downwardly (FIG. 2) with the flexing bead 15 as a fulcrum.

In order to permit the button or flip panel 16 to flex, the flexing bead 15 is used as at general fulcrum point. As shown in detail in FIG. 3, the flexing bead 15 comprises a Wall portion 17 forming a flexing point 17a with the cover portion 2 and a wall portion 18 forming a flexing point 18a with button 16, while the two wall portions 17 and 18 form a flexing point 19 at the apex thereof. The wall portion 18 is at a lesser angle to the horizontal than the wall portion 17 so that when a vacuum is within the container and the button 16 is flexed downwardly the flexing will occur at flexing points 17a, 19 and 18a, as shown in broken lines in FIG. 3, rather than at the shoulder 9 (FIG. 2).

Thus, when there is a vacuum in the container 7, as shown in FIG. 2, the button or flip panel 16 is flexed downwardly whereas if there is no vacuum in the container, as shown in FIG. 1, the button 16 will be flexed upwardly.

With this structure, a housewife may determine whether a package has been tampered with by a visual inspection of the button 16 to see if it is up or down or by applying pressure to the button 16 and if there is an audible click, as the button 16 springs back, it will indicate that there is no vacuum. If there is a vacuum in the container, the button 16 is in its depressed position and there can be no click because the button could not be flexed so that the housewife knows the package has not been tampered with.

In order to permit the button or fiip panel 16 to properly flex upwardly and downwardly with an audible click, the area of the button 16 is approximately one-third of the area of the stacking panel within the periphery of the shoulder 9. This dimension will permit the necessary stresses and strains to be set up when the button 16 is flexed downwardly which are to be relieved for the button 16 to snap up with an audible click. Any wide variation in these dimensions will cause the button 16 to operate improperly.

Likewise, in order to aid in setting up the necessary stresses and strains to permit the button 16 to operate properly, the metal of the cap should be of the proper hardness. If the metal is too soft there may not be enough of a stress and strain set up to cause the flip panel 16 to return, whereas, if the metal is too hard, too much of a stress and strain will be set up for proper operation. For a 48 mm. cap good results have been obtained with a hardness of between 56 and 64 Rockwell reading on a T30 scale and with a 53 mm. cap the hardness as measured on a Rockwell reading on a T30 scale should be between 52 and 60.

The present invention may also be used in connection with the closure cap 1a shown in FIG. 4. The cap 1a comprises a cover portion 2a and a skirt portion 3a having a bead 4a at its lower edge and locking lugs 5a. The cover portion has a gasket-receiving channel 8a which has a portion 9a thereof inclined to the horizontal to receive a gasket 11a in an inclined position as shown in FIG. 4. The inclined gasket 11a, is held in the gasketreceiving channel 8a by an inwardly projecting retaining bead 13a in the skirt portion 3a. The inclined gasket 11a is adapted to cooperate with the inclined sealing surface a and the horizontal sealing surface 12a of the cog container finish 7a and the locking lugs 5a cooperate with thread portion 6a on the container finish to form a sealed package.

The cover portion 2a is provided with a flexing bead 15a which acts as a fulcrum for the dome-shaped flippanel of button 16a. The button 16a and the flexing bead 15a is similar in structure to the button 16 and the flexing bead 15 described in connection with FIGS. 1 to 3, so as to permit the flip-panel 16:1 to flex up or down in a manner similar to the operation as described in connection with FIGS. 1 to 3.

The present invention also provides an improved method of forming the closure of the present invention. This is shown in FIGS. 5 through 9.

The first step (not shown) in the formation of a closure is the stamping out of a cup-shaped closure shell 20 (PEG. 5) having the skirt portion 3, a cover portion 2 and a gasket-receiving channel 8. A depression 22 is also provided on the cover portion 2 which will be subsequently formed into the flexing bead 15 as will be more fully described hereinafter. The edge of the skirt 3 is coaxed-in, as at 21 (FIG. 5), to facilitate the subsequent curling step.

As shown in FIG. 5, the closure shell 20 as thus formed, is inserted in a nest 23 having an ejector 24, provided with a flexing bead-forming supporting edge 25, and the gasket 11 is inserted in the gasket-receiving channel 8. Before the gasket 11 is inserted, a suitable adhesive (not shown) may be applied to the gasket-receiving channel 8 to adhere the gasket 11 in place. It will be noted that the radius of the corner 26 of the shell 20 is greater than the radius of the corner 27 of the nest 23. The large corner radius 26 of the shell 20 is used to locate and center the gasket 11 in the gasket-receiving channel 8 by permitting the gasket 11 to be held in place between corner radius 26 and the shoulder 9 formed by the gasket-receiving channel 3.

A first curling tool 28 then presses down on the coaxedin edge 21 of the shell 20 to form a first curl 29 in the skirt edge, as shown in FTG. 6. At the same time, the radius of the corner 26 of the shell 20 is reformed to conform to the radius of the corner 27 of the nest 23. A suitable pad (not shown) may be used to apply pressure to the gasket 11 so as to adhere the gasket to the shell and hold the gasket in place during the step of reforming the corner radius of the shell 20.

As shown in FIG. 7 the lugs 5 are then formed by a lug-forming tool 29 and, at the same time, the partially curled edge 29 (FIG. 6) of the skirt is curled into a full bead 4 (FIG. 1). The ejector 24 of the nest 23 is then raised as shown in FIG. 8 so as to raise the corner 26 of the closure cap otf the corner 27 of the nest 23 and thereby leave a depression 30 between the corner 37 of the nest and the corner 26 of the cap.

A pressure tool 31 (FIG. 9) now applies downward pressure to the skirt 3 of the closure to reform the metal of the corner 26 of the closure shell downwardly into the depression 30 to form the escapement bead 10 around the peripheral edge between the skirt 3 and the cover 2.

At the same time, a button-forming tool 32 having an annular groove 33 will apply pressure to the cover portion 2 and bulge out the metal of the cover portion 2 to form the button 16 and simultaneously presses the depress 22 against forming ledge on the ejector 24 to reform the depression 22 to conform to the contour of the ledge 25 to complete the flexing bead 15. In this operation the metal is partially stretched to obtain the additional metal necessary to form the flip-panel 16.

The cap will then be ejected from the nest by a subsequent operation.

The closure cap 1a shown in FIG. 4 may be formed by the same method described in connection with FIGS. 5 to 9 except that the step of raising the ejector 24 as shown in F 76. 8 need not be followed since the cap is not provided with an escapement head.

It will be seen that the present invention provides an improved closure cap with an improved vacuum indicating panel which will not deform the gasket-receiving channel and which is so constructed as to permit proper flexing with an audible click. The present invention also provides an improved method of forming the improved cap of the present invention.

As various changes may be made in the form, construction and arrangement of the parts herein without departing from the spirit and scope of the invention, and without sacrificing any of its advantages, it is to be understood that all matter herein is to be interpreted as illustrative and not in a limiting sense.

Having thus described our invention, we claim:

1. A one-piece closure cap having a cover portion and a skirt portion integral with and depending from said cover portion, means on the skirt portion for holding the closure cap on a container, a gasket-containing channel in said cover portion adjacent said skirt portion, said channel having a flat annular gasket-seating portion, a dome-shaped flip panel in said cover portion, a depressed flexing bead in said cover portion to act as a fulcrum for said flip panel, a flat annular zone of said cover portion interposed between and integral with said gasket-containing channel and said flexing bead, the plane of said annular zone being below the plane of the flat annular gasket-seating portion of said gasket-containing channel and being above the plane of said depressed flexing bead.

2. A closure cap as claimed in claim 1, wherein the area of said dome-shaped flip panel is approximately one-third of the area of the cover portion within the periphery of a shoulder therein forming the gasket-receiving channel.

3. A closure cap as claimed in claim 1, wherein the inner wall of said flexing bead is at a lesser angle to the horizontal than the outer wall.

4. A closure cap as claimed in claim 1, wherein the flexing bead has a fulcrum point at the juncture between the inner wall and the flip panel and a fulcrum point at the juncture between the outer wall and said annular zone of said cover portion.

5. A closure cap as claimed in claim 1, wherein said closure cap has a hardness of between 56 and 64 Rockwell reading on a T30 scale.

6. A closure cap as claimed in claim 1, wherein said closure cap has a hardness of between 52 and 60 Rockwell reading on a T30 scale.

References Cited in the file of this patent UNITED STATES PATENTS 1,805,623 Hammer May 19, 1931 2,027,430 Hansen Jan. 14, 1936 2,091,295 Williams Aug. 31, 1937 2,168,565 Gibbs Aug. 8, 1939 2,449,014 Shaffer Sept. 7, 1948 2,458,360 Fay et al Jan. 4, 1949 2,772,018 Weiss Nov. 27, 1956 2,874,863 Unger et al Feb. 24, 1959 2,957,595 White et al Oct. 25, 1960 

